Join 3,512 readers in helping fund MetaFilter (Hide)


Replace radio with aux-in only?
February 24, 2014 10:57 AM   Subscribe

My car radio was stolen last night, and I'd like to turn this tragedy into something awesome. I've always wanted to have a custom setup that consisted only of a volume knob and an aux in. I don't know how to design circutry, but I can follow instructions. What do I need to do to make this work?

I can fabricate the faceplate so it looks exactly like I want; it's the wiring and electrical components that I'm unsure of. I haven't looked at the mess dangling from the empty hole in the dashboard yet, but I'm sure it includes the standard wires:

battery power
starter power
ground
left front
left rear
right front
right rear

There's no power antenna to worry about.

What items do I need to connect that jazz to headphone jack input (and perhaps also SPIDF and/or RCA) + volume knob? How do they need to be wired, where can I order the the necessary circuitry?

I'm hoping to find a sweet old stereo from a thrift store that has the perfect knob to reuse, if possible, but am open to not doing so if that greatly adds to the complexity compared to just purchasing a knob of a certain type. (I think the 70s may have been the height of control knob craftmanship and feel.)

As an aside, are there better sites to post this sort of thing that are perhaps more focussed on this sort of problem?
posted by jsturgill to Technology (11 answers total) 4 users marked this as a favorite
 
Designed for a boat, but this might be useful: Left Coast Simple Stereo
posted by gyusan at 11:11 AM on February 24 [1 favorite]


I never got around to installing my Left Coast Simple Stereo, so I'd be happy to sell it at a substantial discount to a fellow MeFite.

The drawback to the Simple Stereo is that there's no volume control and only two channels (left and right). All the volume control is done from your source device.
posted by Kakkerlak at 11:26 AM on February 24


Not sure if you realize this, but your car stereo had an amplifier in it that took your aux level input and brought it up to the levels that your car speakers require. It won't be as simple as wiring up a jack directly into the wires in your dash.
posted by dobi at 11:31 AM on February 24 [1 favorite]


You will need an amp and something to filter out electrical noise. The 'simple' solution you really want will likely be more expensive than just installing a new stereo with an aux in. However, if you want it exactly like what you describe, you want something like this:

http://www.kicker.com/pxi502

Check caraudio.com or any other car tuning site for more info on custom stereos.
posted by BabeTheBlueOX at 11:47 AM on February 24


I've been thinking of doing the same thing (although I actually would like a radio at times). I am only a basic tinkerer, but something along the lines of a Lepai Tripath or a Pyle amplifier should work for this.
posted by O9scar at 12:00 PM on February 24


I very recently replaced my broken AM/FM/CD/Cassette deck with a simple AM/FM with an aux input and USB input. It was $79 from Crutchfield, and it wasn't even the cheapest option.
posted by COD at 5:56 PM on February 24


I actually have a cheap CD player with aux-in sitting on a shelf in my closet right now. I'm just pursuing this for... well, whatever reasons they are, they aren't practical.

Would this volume knob wired into a 3.5mm jack to RCA input going into an amp like this be a stupid idea?

If so, why? If it's an OK concept, what information should I know before I order a bunch of stuff?

I never got around to installing my Left Coast Simple Stereo, so I'd be happy to sell it at a substantial discount to a fellow MeFite.

Thanks. Keep an eye on your MeMail, maybe, depending on how responses go!

I've been thinking of doing the same thing (although I actually would like a radio at times). I am only a basic tinkerer, but something along the lines of a Lepai Tripath or a Pyle amplifier should work for this.

I'm hoping to be able to, ultimately, have more control over the faceplate. There's a very specific kind of feel that I cherish in stereo equipment, and if I could replicate that here, I'd be an extremely happy camper. But for $30... It seems like a great fallback position.
posted by jsturgill at 9:50 PM on February 24


When I was looking into this exact thing I found that I could run audio out from my phone into a pair of RCA jacks into an amp. Just had to find an amp that would fit in my car.

I also came across a Bluetooth receiver that outputs to RCA jacks, which means I wouldn't even need an aux in, just the volume knob.

I was going to control the volume with my phone, so you'd have to figure out some basic way to have the volume knob connected to the amp. Since my phones volume was controllable with the side buttons, I wasn't worried about that. Conceivably you could just get a Bluetooth remote for a phone and never even have to take the phone out of your pocket.

Then I realized that I spend too much time outside the range of cell towers and just installed a head unit that can accept a USB stick full of mp3s. It has a remote for the volume, so I have it hidden away and just use the remote. The hole where the radio used to be now has a custom made power distribution block for charging and things like cb radios.
posted by BenevolentActor at 12:44 AM on February 25


Two questions about a 24v stereo amp like this one:

1. 24v power. Is it as simple as joining two 12v power wires (constant power and starter), and then connecting them to the DC plug? Will it run when the car's off and it's getting 12v from one of the two lines? Will that damage it?

2. Sound. It's a stereo amp, but it needs to power 4 speakers. Just join both left and right speakers to one wire at the banana plugs, or is that bad and there a better way?
posted by jsturgill at 1:48 PM on February 25


Is there a reason not to use a 'regular' car stereo amplifier?
http://www.amazon.com/Pyle-PLMRA400-4-Channel-Waterproof-Amplifier/dp/B000N5T0T4/ref=sr_1_3?s=car&ie=UTF8&qid=1393366146&sr=1-3

use the bluetooth dongle described by BenevolentActor
http://www.crutchfield.com/S-VJ6IByOp02q/p_822BTREC/Milennia-MIL-BTREC.html

and use the volume on your device?

If you need a knob, just put something between the bluetooth dongle and the amp:
http://www.amazon.com/PAC-Remote-Amplifier-Level-Controller/dp/B0002J226O
posted by kookywon at 2:13 PM on February 25


Is there a reason not to use a 'regular' car stereo amplifier?
http://www.amazon.com/Pyle-PLMRA400-4-Channel-Waterproof-Amplifier/dp/B000N5T0T4/ref=sr_1_3?s=car&ie=UTF8&qid=1393366146&sr=1-3

use the bluetooth dongle described by BenevolentActor
http://www.crutchfield.com/S-VJ6IByOp02q/p_822BTREC/Milennia-MIL-BTREC.html

and use the volume on your device?

If you need a knob, just put something between the bluetooth dongle and the amp:
http://www.amazon.com/PAC-Remote-Amplifier-Level-Controller/dp/B0002J226O


The volume knob isn't something I want to give up.

I'd want to have a 3.5mm in and not just rely on bluetooth. The volume knob would have to affect both inputs.

3.5mm to line in would require an extra step to convert the signal properly. Presumably these other amps have done the work for me.

So with those requirements (user-facing 3.5mm input, automatic switching to 3.5mm if a jack is inserted, line in [bluetooth] if nothing is in the 3.5mm input, volume knob that controls both inputs, and good conversion of the 3.5mm signal to line in), what's the part list centering around a regular car stereo amp? What gets wired into what?
posted by jsturgill at 2:32 PM on February 25


« Older I have dated someone on and of...   |  Help my little family enjoy sp... Newer »

You are not logged in, either login or create an account to post comments